1. Field of the Invention
This invention relates to distributors, and more particularly to an improved distributor for an internal combustion engine in which means are provided for changing the ignition timing depending on variations in the two variables, i.e., the rotating speed of the engine and the load imparted to the engine, so as to minimize the amount of noxious components contained in engine exhaust gases.
2. Description of the Prior Art
There are various methods for reducing the amount of noxious components contained in gases exhausted from internal combustion engines of the spark ignition type. Among these methods, the method of changing the ignition timing depending on the operating condition of the engine is most preferable in that it can effectively reduce the noxious components and it can be most simply put into practical use. Therefore, a suitable ignition timing controller based on this method is desirably used for the engine of this type so that the ignition timing can be changed as desired depending on the operating condition of the engine.
A distributor is commonly known as one form of ignition timing controller heretofore used for the engine of the type above described. This known distributor is generally provided with a centrifugally-actuated ignition advancing unit capable of advancing the ignition timing in proportion to the rotating speed of the engine, and the distributor is also generally connected to a vacuum-actuated ignition advancing unit capable of advancing the ignition timing in inverse proportion to the magnitude of the load imparted to the engine and hence the value of the absolute pressure appearing at the advance port of the carburetor. Although these ignition advancing units in the known distributor are useful means capable of changing the ignition timing depending on the operating condition of the engine in a certain sense, these known ignition advancing units are not fully reliable and effective in reducing the amount of noxious components contained in engine exhaust gases inasmuch as they serve merely to change the ignition timing linearly to the rotational speed of the engine and engine load relative to the standard ignition timing.